Test probe apparatus

ABSTRACT

The test probe is formed by a tubular body member carrying electrical contacts at its front end. An annular slot is formed in the outer portion of the test probe with an elastic ring shaped member located therein. A moveable sleeve is located around the tubular body member for forward and rearward movement relative to the tubular body member. The sleeve has a plurality of angularly spaced apart arms at its front end. In the forward position of the sleeve, the arms are located in the annular slot forcing at least portions of the elastic ring shaped member outward for latching purposes. In the rearward position of the sleeve, its arms are moved rearward of the ring shaped member sufficient to allow it to be released inwardly into the annular slot to an unlatching position. In one embodiment, grooves are formed in the outer surfaces of the arms for receiving the ring shaped member when the sleeve is located in its forward position for releasably holding the sleeve in its forward position. In another embodiment, the arms have no grooves and a second elastic ring shaped member is employed at the rear of the test probe for releaseabaly holding the sleeve in its forward position. In still another embodiment, the forward wall of the annular slot is formed by an inclined surface. The forward edge of the sleeve engages and forces the ring shaped member in the annular slot forward and outward against the inclined surface for latching purposes.

This application is a continuation-in-part of U.S. patent applicationSer. No. 07/050,091, filed on May 14, 1987 and now abandoned entitled"Test Probe".

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a latching apparatus for a test probe and alsoan apparatus in a test probe for routing electrical wires.

2. Description of the Prior Art

Ball and finger type latching mechanisms for latching a test probe in anopening of a device to be tested are well known, for example asdisclosed in U.S. Pat. Nos. Re. 28,328 and 3,505,635. Although veryuseful, these latching mechanisms sometimes come out of the test probeapparatus whereby the test probe apparatus has to be disassembled tocorrect the problem. Springs have been employed in devices for lockingor latching purposes, as shown in U.S. Pat. Nos. 4,355,854 and4,422,704. U.S. Pat. Nos. 4,174,146, 4,364,624, 4,525,016, and 4,602,123disclose different types of devices for routing electrical leads.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a test probe apparatushaving a unique latching mechanism for latching the test probe in anopening of a device to be tested which is easy to replace and which canlatch the test probe in openings of different sizes.

It is another object of the invention to provide a test probe apparatushaving a unique structural arrangement for routing electrical wires.

The test probe apparatus comprises a tubular body means carryingelectrical contact means at its front end. The latching apparatuscomprises an annular slot formed in the outer portion of the test probestructure with an elastic ring shaped member located therein and amoveable sleeve means located around the tubular body means. The sleevemeans is adapted to be moved forward relative to said tubular body meansto move front means thereof into engagement with the ring shaped memberfor moving at least portions of the shaped member outward of the annularslot for latching purposes. The sleeve means is adapted to be movedrearward relative to said tubular body means to move its front meansrearward of the ring shaped member sufficient to allow it to be releasedinwardly into the annular slot to an unlatching position.

Preferably the elastic ring shaped member comprises a helically woundspring member having two ends connected together forming a toroidalshaped spring although it could be a non-metallic elastic ring shapedmember.

In one embodiment, the annular slot is defined by forward and rearwardfacing wall means and inner wall means facing outwardly. At least aportion of said forward facing wall means is spaced radially outwardfrom said inner wall means defining opening means leading to saidannular slot between said forward facing wall means and said inner wallmeans. In the forward position of said sleeve means, said front means ofsaid sleeve means is located between said inner wall means and said ringshaped member forcing at least portions of said ring shaped memberoutward for latching purposes. In this embodiment, preferably said frontmeans of said sleeve means comprises a plurality of angularly spacedapart arm members.

In another embodiment, the outer surface of said front means of saidsleeve means comprises groove means formed therein. In the forwardposition of said sleeve means, said front means of said sleeve means islocated between said inner wall means and said ring shaped member,forcing at least portions of said ring shaped member outward into saidgroove means of said front means of said sleeve means for releaseablyholding said sleeve means in its forward position and for latchingpurposes. In this embodiment, preferably said front means of said sleevemeans comprises a plurality of angularly spaced apart arm members withsaid groove means formed in the outer surfaces of said arm members.

In another embodiment, structure coupled to the front portion of saidtubular body means forms at least a portion of the annular slot andcomprises an inclined surface which extends outward away from said frontportion of said tubular body means. Said front means of said sleevemeans comprises an end wall forming another portion of the annular slotwhich engages and forces said ring shaped member outward against saidinclined surface when said sleeve means is moved toward said forwardposition for moving said ring shaped member outward of the annular slotfor latching purposes.

In a further embodiment, an annular rear slot is formed in the outerwall of the tubular body means and an annular rear slot is formed in theinner wall of said sleeve means. The two annular rear slots are inalignment with each other when said sleeve means is in its forwardposition relative to said tubular body means and out of alignment witheach other when said sleeve means is in its rearward position relativeto said tubular body means. A second elastic ring shaped ember isprovided. The annular rear slot formed in the inner wall of said sleevemeans has a size sufficient to completely receive the second ring shapedmember and the annular rear slot formed in the outer wall of saidtubular body means has a size sufficient to only partially receive thesecond ring shaped member. The second ring shaped member is locatedaround said tubular body means rearward of said annular rear slot formedin said tubular body means and in said annular rear slot formed in saidsleeve means when said sleeve means is in its rearward position and islocated partially in both of said annular rear slots when said sleevemeans is in its forward position for releaseably holding said sleevemeans in its forward position relative to said tubular body means.

Preferably the second elastic ring shaped member comprises a helicallywound spring member having two ends connected together forming atoroidal shaped spring although it could be a non-metallic elastic ringshaped member.

The structural arrangement for routing electrical wires comprises ablock member having a first opening formed into its side and a secondopening formed in its end with said first and second openingsintersecting each other. The rear end of said tubular body means islocated in said first opening and secured to said block member. Saidsleeve means has a rear end which is bifurcated forming two spaced apartend members. Said block member is located in the space between said twospaced apart end members of said sleeve means such that said two endmembers move forward and rearward relative to said block member onopposite sides thereof as said sleeve means is moved between its forwardand rearward positions. The rear end of said tubular body means has anopening formed therethrough in communication with said second opening ofsaid block member forming a passage for said leads out of said tubularbody means.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the one embodiment of test probe of theinvention.

FIG. 2 is an end view of FIG. 1 as seen along the lines 2--2 thereof.

FIG. 3 is a cross-sectional side view of the test probe of FIG. 1 withits latching spring in a latching position.

FIG. 4 is a partial cross-sectional view of the test probe of FIGS. 1and 3 with its latching spring in an unlatched position.

FIG. 5 is a cross-sectional view of the main support member of the testprobe of FIGS. 1 and 3.

FIG. 6 is a cross-sectional side view of a stationary bushing of thetest probe of FIGS. 1 and 3.

FIG. 7 is a forward end view of FIG. 6 taken along lines 7--7 thereof.

FIG. 8 is a rear end view of FIG. 6 taken along the lines 8--8 thereof.

FIG. 9 is a cross-sectional view of the front shell of the test probe ofFIGS. 1 and 3.

FIG. 10 is a cross-sectional top view of the slideable sleeve of thetest probe of FIGS. 1 and 3.

FIG. 11 is an end view of FIG. 10 taken along the lines 11--11 thereof.

FIG. 12 is a cross-sectional view of a rear electrical lead routingblock member of the test probe of FIGS. 1 and 3.

FIG. 13 is an end view of FIG. 12 taken along the lines 13--13 thereof.

FIG. 14 is an end view of FIG. 12 taken along the lines 14--14 thereof.

FIG. 15 is a toroidal shaped coiled spring employed for the latchingmechanism of the test probes of the invention.

FIG. 16 is a side view of another embodiment of the test probe of theinvention.

FIG. 17 is a cross-sectional side view of the test probe of FIG. 16 withits latching spring in a latching position.

FIG. 18 is a cross-sectional view of FIG. 17 taken along the lines18--18 with the electrical contact structure removed.

FIG. 19 is an isometric view of the front portion of the moveable sleeveof FIG. 17 showing its arms and outer grooves formed therein.

FIG. 20 is a cross-sectional view of the rear portion of the sleeve ofthe test probe of FIG. 17.

FIG. 21 is an end view of FIG. 20 taken along the lines 21--21 thereof.

FIG. 22 is a cross-sectional view of a housing breech into which thetest probe may be inserted and latched for testing electrical componentsof equipment coupled to the housing breech.

FIG. 23 is a side view of another embodiment of the test probe of theinvention.

FIG. 24 is a cross-sectional side view of the test probe of FIG. 23.

FIG. 25 is a cross-sectional side view of the sleeve of the test probeof FIG. 24.

FIG. 26 is a front view of the sleeve of FIG. 25 as seen along the lines26--26 thereof.

FIG. 27 is a cross-sectional side view of the bushing of the test probeof FIG. 24.

FIG. 28 is a front end view of the bushing of FIG. 27 taken along thelines 28--28 thereof.

FIG. 29 is a side view of another embodiment of the test probe of theinvention.

FIG. 30 is a cross-sectional side view of the test probe of FIG. 29 withits slideable sleeve in a forward position.

FIG. 31 is a cross-sectional view of the test probe of FIG. 29 with itsslideable sleeve in a rearward position.

FIG. 32 is a cross-sectional side view of the moveable sleeve of thetest probe of FIG. 29.

FIG. 33 is a front view of the sleeve of FIG. 32 taken along the lines33--33 thereof.

FIG. 34 is a cross-sectional side view of the mount of the test probe ofFIG. 29.

FIG. 35 is a rear end view of the mount of FIG. 34 taken along the lines35--35 thereof.

FIG. 36 is an elastic non-metallic ring shaped member which may beemployed in the test probes of the invention.

FIG. 37 is a cross-section of FIG. 36 taken along the lines 37--37thereof.

FIG. 38 is a cross-sectional side view of another embodiment of the testprobe of the invention.

FIG. 39 is a partial cross-sectional view of the test probe of FIG. 38with its latching spring in an unlatched position.

FIG. 40 is modification of the sleeve component of FIG. 32.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, the test probe of the embodiment of FIGS.1-15 of the invention is identified at 21. It comprises a hollowcylindrical shaped body member 23 having a front end 23A, a rear end23B, and a central cavity 23C. Three clearance apertures 25 (only one ofwhich is shown) are formed through the wall of the body member 23 at itsfront end. The rear end 23B of the body member 23 has two annulargrooves 27 and 29 formed in its outside wall. A threaded aperture 31 isformed through the side wall of member 23 at its rear end and a threadedaperture 33 is formed through its rear wall 23D. A large opening 35 alsois formed through the wall of member 23 at its rear end for the passageof electrical leads.

A bushing 51 is secured around the front end 23A of the member 23 by setscrews one of which is shown at 53. The bushing 51 has a frontcylindrical wall 51A and a larger diameter rear cylindrical wall 51Bwith an axial opening 55 formed therethrough. Three clearance apertures57 (only one of which is shown) are formed through the front wall 51Afor receiving the set screws 53. The front and rear walls 51A and 51Bare connected together by a radially extending wall 51C which has fouropenings 59 formed therethrough. The centers of adjacent openings 59 are90° apart.

Secured around the front part of the bushing 51 and hence to the frontend 23A of the body member 23 is a shell member 61 which is cylindricalin shape having an opening 63 extending axially therethrough. The sidewall of the shell member has three threaded apertures 65 (only one ofwhich is shown) formed therethrough for receiving the set screws 53. Thecenters of adjacent apertures 25 of body member 23 are 120° apart; thecenters of adjacent apertures 57 of the bushing 51 are 120° apart; andthe centers of adjacent apertures 65 of the shell 61 are 120° apartwhereby the three set screws 53 secure the bushing 51 and the shell 61to the body member 23. The set screws 53 when screwed into the apertures65 of the shell 61 extend through the apertures 57 and 25 of the bushing51 and of the body member 23 and bear against a tubular insert 71,holding it and the shell 61 and bushing 51 in place to the body member23, as shown. The front end of the shell member 61 has an inwardextending annular lip 67.

The hollow tubular insert 71 formed of a suitable electricallyinsulating plastic material is located in the front end of the cavity23C of the member 23. The insert 71 has a radially extending flange 71Aat its front end which seats against the front edge of member 23. Ahollow metallic tubular member 73 is located in the front end of anenlarged diameter portion 71B at the front end of the insert 71. Member73 has a radially extending flange 73A at its front end which seatsagainst the front edge of the insert 71.

An annular electrical contact member 81 formed of metal, is provided atthe front end of the probe 21 for forward and rearward movement. Therear portion of the contact 81 is located for rearward and forwardmovement in the annular space 83 between member 23 and flange 71A andshell 61. The lip 67 of the shell 61 is adapted to engage an outwardextending wall 81A of the contact 81 at its rear end for limitingforward movement of the contact 81. A metallic coiled spring 85 locatedagainst the inside wall of the contact 81 and against the flange 73A ofmember 73 urges the contact 81 outward and provides an electricalconnection between the contact 81 and member 73. Member 73 makeselectrical contact with a metallic tubular member 87 located in theopening of the insert 71 to which an electrical lead 89 is connected.

Secured within the tubular member 87 is an electrical insulating sleeve91 which engages and holds a thin metal tubular member 93. The rear endof member 93 has metallic member 95 located and secured therein bycrimping the thin wall of the tubular member 93 to member 95, as shownat 93A. The rear end of member 95 is connected to an electrical lead 99and the other end has an aperture 101 for slideably receiving thepin-like rear end 103A of a central contact 103. The forward end 103B ofthe contact 103 extends through a central aperture 81B of the annularcontact 81 without engagement thereof. A coiled metallic spring 105 hasits front end tightly located around an intermediate portion 103C of thecontact 103 and its rear end engaging a forward facing wall of member 95inside of tubular member 93. Coil 105 urges contact 103 in a forwardposition and provides electrical connection between contact 103 andmember 95. A forward inward extending lip 93B of tubular member 93limits forward movement of the contact 103. Leads 89 and 99 extendrearward where they are connected to terminals which extend out of theprobe as will be described subsequently.

In using the test probe, its forward end is inserted into the opening orwell formed in metal structure of an aircraft or other equipment suchthat its annular contact 81 engages the back wall of the opening and itscentral contact 103 is centered relative to an aperture formed throughthe back wall for engaging an electrical contact of circuitry of theaircraft to be tested.

The test probe of the invention has a helical coil formed in the shapeof a toroid for latching the probe in the opening. The coil isillustrated at 121 and is formed by spring type metal wire helicallywound to form a helical coil having two ends 123 and 125 with a centralopening within the coil turns 121A which extends between the ends 123and 125. A threaded member 127 then is screwed into the two ends 123 and125 to bring them together to form the toroidal shaped coil 121 whichcan be expanded radially outward from its axis 129. When released thecoil will retract radially inward toward its normal position, as shownin FIG. 15.

The coil 121 is located in the annular slot 131 formed between the rearend 61B of the shell 61 and the forward edge 51BF of the rear wall 51Bof the bushing 51.

An axially moveable sleeve 141 is employed for expanding the coil 121radially outward to a latching position and for releasing the coil toits unlatched position in the slot 131. The sleeve 141 is generallycylindrical in shape at its forward portion 141A having an opening 143extending axially therethrough. Its front end 141A has four spaced apartslots 145 formed rearward from its forward edge 141FE to form four armsor fingers 147 which are of a size and are located such that they mayslide through the four openings 59 of the bushing 51. The front edges147A of the arms 147 taper toward the axis in a forward direction, asshown in FIGS. 3, 4, and 10. The sleeve 141 is fitted around the bodymember 23 from its rear end. The inside diameter of the opening 143 atthe forward end of the sleeve 141 is large enough to fit around theenlarged forward portion 51AF of the bushing 51 whereby the arms 147 maybe inserted through the openings 59 of the bushing 51. The sleeve 141may be moved to a rearward unlatched position, as shown in FIG. 4, or toa forward latched position, as shown in FIG. 3. In the unlatchedposition, the tension of the spring 121 causes it to move radiallyinward whereby its inner surface engages the bushing surface 51AF suchthat its outer surface does not protrude radially outward beyond themaximum diameters of the shell 61 and the bushing 51, as shown in FIG.3. In this position, the spring 121 is in an unlatched position. Theoutside diameter of bushing portion 51AF is slightly greater than thenormal inside diameter of the spring 121 whereby it is tightly held byits tension within the slot 131 when the sleeve 141 is in its rearwardunlatched position.

When sleeve 141 is moved to a forward latched position, the taperededges 147A of the arms 147 move "under" the spring 121 causing it toride "up" the tapered edges 147A and to seat on the outer surface of theforward portion 141A of the sleeve 141 at the four positions of the arms147. This causes the spring 121 at the positions of the arms 147 toextend radially outward beyond the maximum diameters of the shell 61 andthe bushing 51 whereby the spring 121 may latch the test probe to theinside wall of the opening of the aircraft structure. References aremade to U.S. Pat. No. 3,505,635 for a disclosure of the wall of anopening to which the probe may be latched. FIG. 22 also shows a hollowmetal housing breech 212 having an opening 213 into which the frontportion of the test probe 21 may be inserted and the spring 121 latchedinto groove 215 for latching the probe 21 within the opening 213 of thehousing breech 212. The forward edge of the contact 81 will engage thewall 217 of the housing breech and the contact 103 will engage a pincontact (not shown) of the equipment to be tested through opening 219formed through the wall 217.

The rear portion 141B of the sleeve 141 is bifurcated forming two spacedapart end members 161 and 163 having space 143A therebetween. Theopening 143 narrows to a smaller diameter rear opening 143B which has adiameter equal to the distance between the inside surfaces 161A and 163Aof members 161 and 163. The rear inside surface 141C of the sleeve 141slides on the rear portion 23B of the member 23 at the slots 27 and 29as the sleeve is moved to its forward and rearward positions. The rearend of the sleeve 141 has one or more apertures 165 formed therein fromthe inside, each of which has a spring 167 and a ball 169 locatedtherein. The springs 167 force the balls 169 inward into either ofannular slots 27 or 29 when the sleeve 141 is moved to its rearward orforward positions. Thus, the balls 169 are releaseably held in either ofslots 27 or 29 by the springs 167 for releaseably holding the sleeve 141in either its rearward or forward positions. An aperture 171 is locatedopposite each of apertures 165 and are used to facilitate drillingapertures 165 after which the apertures 171 are closed by set screws172. The rear slanted surface 175 of the shell 61 will engage thetapered edges 147A of the arms 147 if the sleeve 141 is moved furtherforward than that shown in FIG. 3 and limits the maximum forwardposition of the sleeve 141.

Located and secured within the space 143A between the end members 161and 163 is an elongated block member 181. Member 181 has four sides182-185 and two ends 186 and 187 with an opening 189 formed through theend 187 which extends toward end 186 along the length of member 181until it intersects an opening 191 formed into side 183 transversely tothe length of member 181. A threaded aperture 193 is formed into end 186intersecting opening 191 and an opening 195 is formed into side 185intersecting opening 191.

The rearmost portion 23E of the body member 23 (rearward of slots 27 and29) has a small outside diameter which is adapted to fit in the opening191 of the block member 181. In assembly, the block member 181 islocated in the space 143A between members 161 and 163 with the endportion 23E of body member 23 located in the opening 191. The blockmember 181 is secured to the body member 23 by screwing a bolt 197 intothreaded apertures 193 and 31 of members 181 and 23 and inserting a bolt199 through aperture 195 of member 181 and screwing it into aperture 33of member 23.

When the sleeve 141 is moved between its rearward and forward positions,members 161 and 163 slide or move past the sides 182 and 184respectively of the block member 181. The block member 181 limitsrearward movement of the sleeve 141.

The leads 89 and 99 are extended through rear opening 35 of member 23into the opening 189 of member 181 and are connected to two terminals201 and 203 supported by electrical insulating material 205 located inthe opening 189 at the threaded end 187. Terminals 201 and 203 areconnected to other terminals of the test equipment which is not shown.

The spring 121 provides an effective latching mechanism that is easy toinstall and replace if necessary. In addition, it allows a given testprobe to be fitted into and latched in different diameter openingswithin certain limits whereby a different diameter test probe will notbe needed for each housing breech of a different diameter. In thepreferred embodiment, a spring of the type shown at 121 in FIG. 15 isemployed in the slot 131 for latching purposes. In another embodiment,an elastic ring member of a suitable plastic, such as a teflon coveredsilicone "O" ring, as shown at 211 in FIGS. 36 and 37, may be employedin the slot 131 instead of the spring 121. The bifurcated sleeve 141 andthe lead routing block 181 provides a compact arrangement for routingthe leads 90° from the forward contacts. It is to be understood that thebody member 23 and sleeve 141 can be made shorter or longer as desired.

The test probe of FIGS. 16-21 is similar to that of FIGS. 1-15, exceptthe tubular body member 23 and the sleeve 141 of the embodiment of FIGS.1-15 are different in the embodiment of FIGS. 16-21. In FIGS. 1-15 and16-21, like reference numerals identify like components. In FIGS. 16-21,the tubular body member corresponding to the tubular body member 23 ofFIGS. 1-15 is identified at 223. Member 223 is the same as member 23,except that the annular grooves or slots 27 and 29 are not present inthe member 223.

In FIGS. 16-21, the sleeve corresponding to sleeve 141 of FIGS. 1-15 isidentified at 241 and is formed by two sleeve components 243 and 245connected together by a split metal spring ring 247. The sleevecomponent 243 has a forward portion 249 and a rear portion 251 with acentral aperture 253 extending therethrough. The inside and outsidesurfaces of the forward portion 249 are cylindrical and the insidesurface of the rear portion 251 is cylindrical having an inside diameterless than that of the forward portion 249. The rear portion 251 canfreely slide around the tubular member 223. The front end of the forwardportion 249 has four spaced apart slots 255 formed therein rearward ofits forward edge 249FE forming four angularly spaced apart arms 257which are of a size such that they can pass through the four openings 59of the bushing 51 and slide on the outer surface 51AF of the bushing 51.A groove 261 is formed in the outside surface of each of the arms 257.The rear portion 251 has an outside diameter smaller than that of theforward portion 249 and tapers inward toward its rear end. An annularslot 263 is formed in the outer surface of the rear portion 251 forreceiving a portion of the split ring 247.

The sleeve component 245 has a central opening 265 formed therethrough.It comprises a forward hollow cylindrical portion 267 having an insidediameter sufficient to fit around the rear portion 251 of component 243and a rear hollow cylindrical portion 269 having an inside diametersufficient to fit around and slide freely on the tubular body member223. An annular slot 271 is formed in the inside wall of the cylindricalportion 267 and is capable of completely receiving the split ring 247 toallow the rear portion 251 of component 243 to be inserted within thecentral opening of the cylindrical portion 267 of component 245 untilthe slots 263 and 271 are aligned at which position the split ring 247locates partially within both slots 263 and 271 to connect the sleevecomponents 243 and 245 together.

The rear portion of sleeve component 245 is bifurcated forming twospaced apart end members 281 and 283 having space 285 therebetween. Thediameter of the opening 265A of rear cylindrical portion 269 is equal tothe distance between the inside surfaced 281A and 283A of members 281and 283. The block member 181 of the test probe is located in the space285 between members 281 and 283 whereby the members 281 and 283 willslide or move relative to the sides of the block member 181 as thesleeve 243 is moved between its forward position as shown and FIG. 17and its rearward position wherein the rear end 296A of rear cylindricalportion 269 of the sleeve component 245 abuts against the block member181 which limits rearward movement of the sleeve 243.

When the sleeve 243 is in its rearward position relative to the tubularbody member 223, the arms or cams 257 are moved rearward of the annularslot 131 and the spring member 121 seats on the annular bushing surface51AF such that the outer surface of the spring 121 does not protruderadially outward beyond the maximum diameters of the shell 61 and thebushing 151. When the sleeve 243 is moved to its forward positionrelative to the tubular body member 223, the tapered forward edges 257Aof the arms 257 move "under" the spring 121 causing it to ride "up" thetapered edges 257A and to seat in the grooves 261 of the arm members257. This position of the spring 121 in the slot 131 and in the twogrooves 261 of each of the arms 257 allows the spring 121 to releaseablyhold the sleeve 243 in its forward latching position. In addition, thespring 121 at the apex 257B of each of the arms 257 between its twogrooves 261 extends radially outward of the annular slot 131 beyond themaximum diameters of the shell 61 and the bushing 51 whereby the spring121 may latch the test probe in the inside wall of the opening of thestructure to be tested. This arrangement allows the sleeve 243 to beeffectively held in its forward latching position without the need ofthe releaseable holding arrangement comprising the springs 167 and theballs 169 of the embodiment of FIGS. 1-15 which is more difficult toform and is not as effective as the spring 121 in combination with thegrooves 261 for releaseably holding the sleeve 243 in its forwardposition. In order to move the sleeve to its rearward position, onemerely needs to move the sleeve 243 rearward relative to the tubularbody member 223 by engaging the outer portion of the sleeve 243 whilethe test probe is latched in the opening and moving the sleeve 243rearward. The latching spring 121 has the same advantages as that of theembodiment of FIGS. 1-15 in that it will effectively latch the testprobe in an opening and is easy to install and replace if necessary. Inaddition, the latching mechanism allows a given test probe to be fittedinto and latched in different diameter openings within certain limitswhereby a different diameter test probe will not be needed for eachhousing breech of a different diameter. In the preferred embodiment, thespring 121 is employed in the slot 131 for latching purposes and forreleaseably holding the sleeve 243 in its forward position, however, theelastic ring member 211 of FIGS. 36 and 37 may be employed instead inthe slot 131 for the same purposes.

The test probe of FIGS. 23-28 is similar to that of FIGS. 16-21 exceptthat the bushing member and shell have been slightly modified; the block181 removed; and the tubular body member and the rear component of themoveable sleeve have been modified to allow the insulating block 205carrying the terminals 201 and 203 to which the leads 89 and 99 areconnected to be located in the rear end of the tubular body member. InFIGS. 16-21 and 23-28, like reference numerals identify like components.In FIGS. 23-28, the bushing member, the shell, the tubular body member,and the sleeve corresponding to components 51, 61, 223, and 243 or FIGS.16-21 are identified at 351, 361, 323, and 343 respectively.

Bushing 351 is the same as bushing 51 except that its front cylindricalwall 351A has the same outside diameter along its entire length and inaddition, it has three outwardly extending studs 351B through which theapertures 57 extend.

The shell 361 is the same as shell 61 except that its outer surface istapered at its front end and it has only one outside diameter at itsrear portion.

The tubular body member 323 is similar to tubular body member 223 exceptfor the following. Member 323 has an annular slot 325 formed in its rearportion for receiving a split ring 327 which acts as a rear stop for thesleeve 343. In addition, member 323 has no rear side opening for leadsand the insulating member 205 for holding the terminals 201 and 203 islocated in the rear portion of its central cavity 323C. Also the rearend of member 323 has an axial opening at 329 for leads to be connectedto terminals 201 and 203 and its rear end is threaded at 331 to which asleeve 333 is screwed for receiving a lead routing fitting of the type,for example, as disclosed in U.S. Pat. No. 4,602,123. The forward sleevecomponent 249 of sleeve 343 is the same as that of FIG. 17 in that ithas arms 257 at its forward end with outer grooves 261 with the arms 257being insertable through the openings 59 of the bushing 351 and theirinner surfaces being slideable on the forward cylindrical portion 351Aof the bushing 351 whereby they may be located between the cylindricalportion 351A and the spring 121 urging the spring outward in the slot131 and into the outer grooves 261 of the arms for releaseably holdingthe sleeve 343 in its forward position and for holding the spring 121outward of the slot 131 at the positions of the arms 257 for latchingpurposes. The sleeve 343 may be moved to its rearward position where itis stopped by the split ring 327. At this position, the arms 257 aremoved from under the spring 121 to allow the spring to be releasedinward against the cylindrical surface 351A to an unlatched positionwhere it does not protrude outward beyond the bushing 351 and the shell361. The rear cylindrical component 345 is the same as the rearcomponent 45 of FIG. 17 except that its rear end is cut short and itdoes not have the members 281 and 283 of the sleeve component 245 ofFIG. 17.

In the preferred embodiment of FIGS. 23-28, the spring 121 is employedin the slot 131 for latching purposes, however, the elastic ring member211 of FIGS. 36 and 37 may be employed instead in the slot 131 forlatching purposes. An elastic "O" ring 291 also may be located aroundthe rear of the sleeve component 249 to help stabilize the test probe inthe opening in which it is to be latched.

The test probe of FIGS. 29-35 is similar to that of FIGS. 23-28 exceptthat a mount and a shell have been substituted for the shell and bushingrespectively and a separate bushing is located between the mount and thetubular body member. In addition, the arms 257 of the sleeve component249 have no outer grooves and a separate elastic ring member is employedto aid in releaseably holding the sleeve in its forward position. InFIGS. 23-28 abd 29-35, like reference numerals identify like components.Referring to FIGS. 29-35, the tubular body member 323 is similar to thatof FIG. 24 except that it is shorter and it has an annular slot 425formed in its rear portion for receiving a toroidal shaped spring 427similar to that of spring 121 but of a smaller diameter. The sleeve 343is the same as that of 343 of FIG. 24 and comprises the forwardcomponent 249 and the rear component 345 which are connected together bythe split ring 247. The arms 257 are thinner in cross-section and do nothave the tapered front edges or the outer grooves 261. The rearcomponent 345 has an annular slot 429 formed in its inner wall which ithas a size sufficient to completely receive the spring ring member 427.The slot 425 formed in the tubular body member 323 can only partiallyreceive the spring ring member 427. When the sleeve 343 is moved to itsrearward position, the split ring 327 limits its rearward position andthe spring member 427 is rolled out of the slot 425 and is located inthe slot 429 around the tubular member 343 rearward of the slot 425, asshown in FIG. 31. When the sleeve 343 is moved to its forward position,the spring 427 is rolled forward on the outer surface of the tubularbody member 323 until both of the slots 425 and 429 are in alignment andthe spring member 427 is located partially in both slots 425 and 429 toreleaseably hold the sleeve member in its forward position.

The slot 131 for holding the latching spring 121 is located near theforward end of the test probe. When the sleeve 343 is moved to itsforward position, the spring 121 acts to latch the test probe in theopening of a housing breech.

In the embodiment of FIGS. 29-35, the annular slot 131 is formed at itsforward end by the mount member 431 and a shell 433. A bushing 435,which is a hollow cylindrical member fits around the forward portion ofthe tubular body member 323. The mount 431 is formed by a hollowcylindrical shaped portion 441 with a rim 443 formed at its forward end.The rim 443 has a portion 445 which extends radially inward of thecylindrical portion 441 for retaining or limiting forward movement ofthe contact member 81. The rim 443 has a radially outward extendingportion 447 with a rearward facing surface 449 which acts as the forwardportion of the slot 131. Four angularly spaced apart stud members 451extend radially outward from the cylindrical portion 441 at the rearthrough which four clearance apertures 453 extend. The bushing 435 alsohas four angularly spaced apart clearance apertures 455 formedtherethrough which are in alignment with the apertures 453 of the mountmember 431. The shell 433 is a hollow cylindrical member which has fourangularly spaced apart threaded apertures 457 formed therethrough. Thefront of the tubular body member 323 also has four angularly spacedapart clearance apertures 459 formed therethrough. When members 323,435, 431, and 433 are fitted together, as shown in FIG. 30, the foursets of apertures 459, 455, 453, and 457 are in alignment and four setscrews 461 are screwed through the apertures 457 such that they passthrough apertures 453, 455, and 459 until they bear against the tubularinsert 71 to secure the shell 433, the mount 431, the bushing 435 andthe tubular insert 71 to the tubular body member 323, as shown in FIG.30. In this position, the forward surface 463 of the shell 433 forms therear edge of the slot 131 and the rear surface 449 of the rim portion447 forms the forward edge of the slot 131. The inner surface of theslot 131 is formed by the outer surface of the forward portion 441A ofthe cylindrical portion 441 of the mount 431. The four studs 451 formapertures or openings 471 between adjacent studs and between thecylindrical wall 441 of the mount and the outer shell 433 (a portion ofwhich is shown in FIG. 35) for receiving the arms 257 of the forwardcomponent 249 of the sleeve 343. In the forward position of the sleeve,the arms 257 slide on the cylindrical wall 441 of the mount 431 and urgethe spring 121 radially outward at the position of the arms 257 wherebythe spring 121, at the position of the arms 257, will be locatedradially outward of the outermost portion 447 of the rim 443 andradially outward of the shell 433 to latching positions.

In the preferred embodiment of FIGS. 29-35, the spring ring 121 isemployed in the slot 131 for latching purposes and the spring ring 427is employed in the slots 425 and 429 for releaseably holding the sleevein its forward position, however, elastic ring members, similar to thatshown at 211 in FIGS. 36 and 37, and of the appropriate diameters, maybe employed instead in the slot 131 and in the slots 425 and 429 for thesame purposes respectively.

Referring now to FIGS. 38 and 39, the test probe shown therein issimilar to the test probe of FIGS. 29-35 except the front mount memberand the forward component of the moveable sleeve have been modified andin addition the outer shell has been removed. In FIGS. 29-35, 38 and 39like reference numerals identify like components. The front mount member531 is formed by a hollow cylindrical shaped member 541 with a rim 543formed at its forward end. The rim 543 has a portion 545 which extendsradially inward from the cylindrical shaped portion 541 for retaining orlimiting forward movement of the contact member 81. The rim 543 has aradially outward extending portion 547 with a rearward facing inclinedsurface 549 which acts as the forward portion of the annular slot 131.The cylindrical shaped portion 541 is adapted to be fitted around thebushing 435 and has four angularly spaced apart threaded apertures 553formed therethrough for receiving four set screws 561. When members 323,435, and 541 are fitted together as shown in FIG. 38, the three sets ofapertures 459, 455, and 533 are in alignment respectively and the fourset screws 561 are screwed through the apertures 553 such that they passthrough apertures 455 and 459 until they bear against the tubular insert71 to secure the mount 541, the bushing 435, and the tubular insert 71to the tubular member 323, as shown in FIG. 38. When screwed in place,the set screws 561 do not extend outward beyond the outer surface of thecylindrical shaped member 541.

The sleeve component 649 has a rear portion 649A with a cylindricalinside wall 651 that is slideably located around the tubular body member323 and an annular slot 653 formed in its outer wall for receiving thesplit ring 247 for connecting together the sleeve components 345 and 649of the sleeve 343. The forward portion 649B of the sleeve component 649has an inside cylindrical wall 655 that is slideably located around thecylindrical portion 541 of the mount 531. The forward edge 657 of thesleeve component is circular (it has no arms or fingers) 649 and formsthe rear portion of the annular slot 131. The ring shaped member 121 islocated in the slot 131. The sleeve 343 comprising the sleeve components345 and 649 is adapted to move between a rearward position where itabuts against the ring stop 327 and a forward position, as shown in FIG.38. In the rearward position of the sleeve 343, the spring ring 427 islocated in the position as shown in FIG. 31 and the spring ring 121 islocated in an unlatched position against the cylindrical portion 541rearward of the inclined surface or ramp 541 such that it does notextend outward beyond the rim 547 and the outer surface of the sleeveportion 649B. When the sleeve 343 is moved to its forward position, thefront edge 657 of sleeve component 649 engages the spring ring 121 andforces it forward and outward against the inclined surface 549 to alatching position where it extends outward beyond the rim 547 and theouter surface of the sleeve component 541, as shown in FIG. 38. In thisposition of the sleeve 343, the spring ring 427 is located partially inboth annular slots 425 and 427 releaseably holding the sleeve 343 in itsforward position. When the sleeve 343 is moved rearward, the spring ring121 slides or rolls rearward and inward against the inclined surface 549to the unlatching position, as shown in FIG. 39.

In the preferred embodiment of FIGS. 38 and 39, the spring ring 121 isemployed in the slot 131 for latching purposes and the spring ring 427is employed in the slots 425 and 429 for releaseably holding the sleeve343 in its forward position, however, elastic ring members, similar tothat shown at 211 in FIGS. 36 and 37 and of appropriate diameters, maybe employed instead in the slot 131 and in the slots 425 and 429 for thesame purposes respectively.

In the embodiments of FIGS. 29-35, 38, and 39, the use of the rearresilient or elastic ring shaped member (spring 427 or the member 211)in the slots 425 and 429 for releaseably holding the sleeve in itsforward position has advantages over the balls 169 and springs 167 shownin FIG. 3 in that the elastic ring member is easier to install andremove and will not come out of the slots.

In the embodiments of FIGS. 16-21, 23-28, and 29-35, the elastic ringshaped member (spring 121 or member 211) in the slot 131 in combinationwith the stop (block 181 or split ring 327) also acts to releaseablyhold the sleeve in its rearward position, since forward force must beapplied to force the arms of the sleeve under the elastic ring member inthe slot 131 to force the elastic ring member outward for latchingpurposes.

In the embodiments of FIGS. 29-35, 38, and 39, the rear elastic ringshaped member (spring 427 or member 211) also acts to releaseably holdthe sleeve in its rearward position, since forward force must be appliedto the sleeve relative to the tubular body member to roll the elasticring member forward around the tubular body member 323.

If desired, in the embodiment of FIGS. 29-35, grooves can be formed inthe outer surfaces of the arms 257 of the sleeve component 249 neartheir forward ends, as shown at 261 in FIG. 40, for receiving theelastic ring shaped member (spring 121 or member 211) in the slot 131when the sleeve is in its forward position to perform the function offorcing portions of the ring shaped member outward of the slot 131 forlatching purposes and also to aid the ring shaped member in the slots425 and 429 in releaseably holding the sleeve in its forward position.

I claim:
 1. A test probe apparatus, comprising:tubular body means havinga front end and a rear end, structure including electrical contact meanssupported at said front end of said tubular body means, electrical leadsconnected to said electrical contact means and extending through saidtubular body means towards said rear end, structure coupled to the frontportion of said tubular body means forming an outer annular slot, saidannular slot being defined by forward and rearward facing wall means andinner wall means facing outward, said forward and rearward facing wallmeans and said inner wall means being secured in place relative to saidtubular body member, at least a portion of said forward facing wallmeans being spaced radially outward from said inner wall means definingopening means leading to said annular slot between said forward facingwall means and said inner wall means, a ring shaped member located insaid annular slot, said ring shaped member being of the type that can beexpanded outward from its axis and when released it will retractinwardly, an axially movable sleeve means located around said tubularbody means, said sleeve means being adapted to be moved between rearwardand forward positions relative to said tubular body means, at least theforward portion of said sleeve means being movable is said openingmeans, said sleeve means having front means adapted to be locatedbetween said inner wall means and at least portions of said ring shapedmember when said sleeve means is moved toward said forward position formoving at least portions of said ring shaped member outward of saidannular slot for use for latching said test probe apparatus to structureof an opening, in said rearward position of said sleeve means, saidfront means of said sleeve means is located rearward of said ring shapedmember sufficient to allow it to be released inwardly in said annularslot to an unlatching position.
 2. The test probe apparatus of claim 1,wherein said ring shaped member comprises a helically wound springmember having two ends connected together forming a toroidal shapedspring.
 3. The test probe apparatus of claim 1, wherein said ring shapedmember comprises a non-metallic elastic member.
 4. The test probeapparatus of claim 1, wherein:said sleeve means has a central axis, saidfront means of said sleeve means comprises a plurality of angularlyspaced apart arm means located around said central axis, each of saidarm means having an outer surface defined by two outer side edgesextending to an outer central portion, each of said arm means havinggrooves formed in its outer side edges on each side of its outer centralportion with its outer central portion having no groove formed therein.5. The test apparatus of claim 4, comprisinggroove means formed in theouter surface of said front means of said sleeve means, in said forwardposition of said sleeve means, said front means of said sleeve means islocated between said inner wall means and said ring shaped memberforcing at least portions of said ring shaped member outward into saidgrove means of said sleeve means for releasably holding said sleevemeans in its forward position relative to said tubular body means andfor use for latching said test probe apparatus to structure of anopening.
 6. The test probe apparatus of claim 4, comprising:an annularrear slot formed in the outer wall of said tubular body means, anannular rear slot formed in the inner wall of said sleeve means, saidannular rear slots being formed in said tubular body means and in saidsleeve means such that they are in alignment with each other when saidsleeve means is in its forward position relative to said tubular bodymeans and out of alignment with each other when said sleeve means is inits rearward position relative to said tubular body means, a second ringshaped member being of the type that can be expanded outward from itsaxis and when released it will retract inwardly, said annular rear slotformed in the inner wall of said sleeve means having a size sufficientto completely receive said second ring shaped member, said annular rearslot formed in the outer wall of said tubular body means having a sizesufficient to only partially receive said-second ring shaped member,said second ring shaped member being located around said tubular bodymeans out of and rearward of said annular rear slot formed in saidtubular body means and in said annular rear slot formed in said sleevemeans when said sleeve means is in its rearward position relative tosaid tubular body means, said second ring shaped member being locatedpartially in both of said annular rear slots when said sleeve means isin its forward position relative to said tubular body means forreleaseably holding said sleeve means in its forward position relativeto said tubular body means.
 7. A test probe apparatus,comprising:tubular body means having a front end and a rear end,structure including electrical contact means supported at said front endof said tubular body means, electrical leads connected to saidelectrical contact means and extending through said tubular body meanstowards said rear end, structure coupled to the front portion of saidtubular body means forming at least a portion of an outer annular slot,a ring shaped member located in said annular slot, said ring shapedmember being of the type that can be expanded outward form its axis andwhen released it will retract inwardly, an axially movable sleeve meanslocated around said tubular body means, said sleeve means being adaptedto be moved between rearward and forward positions relative to saidtubular body means, said sleeve means having front means adapted toengage at least portions of said ring shaped member when said sleevemeans is moved toward said forward position for moving at least portionsof said ring shaped member outward of said annular slot for use forlatching said test probe apparatus to structure of an opening, in saidrearward position of said sleeve means, said front means of said sleevemeans is located rearward of said ring shaped member sufficient to allowit to be released inwardly in said annular slot to an unlatchingposition. an annular rear slot formed in the outer wall of said tubularbody means, an annular rear slot formed in the inner wall of said sleevemeans, said annular rear slots being formed in said tubular body meansand in said sleeve means such that they are in alignment with each otherwhen said sleeve means is in its forward position relative to saidtubular body means and out of alignment with each other when said sleevemeans is in its rearward position relative to said tubular body means, asecond ring shaped member being of the type that can be expanded outwardform its axis and when released it will retract inwardly, said annularrear slot formed in the inner wall of said sleeve means having a sizesufficient to completely receive said second ring shaped member, saidannular rear slot formed in the outer wall of said tubular body meanshaving a size sufficient to only partially receive said second ringshaped member, said second ring shaped member being located around saidtubular body means out of and rearward of said annular rear slot formedin said tubular body means and in said annular rear slot formed in saidsleeve means when said sleeve means is in its rearward position relativeto said tubular body means, said second ring shaped member being locatedpartially in both of said annular rear slots when said sleeve means isin its forward position relative to said tubular body means forreleasably holding said sleeve means in its forward position relative tosaid tubular body means.
 8. The test probe apparatus of claim 7, whereinsaid second ring shaped member comprises a helically wound spring memberhaving two ends connected together forming a toroidal shaped spring. 9.The test probe apparatus of claim 7, wherein said second ring shapedmember comprises a non-metallic elastic member.
 10. A test probeapparatus, comprising:tubular body means having a front end and a rearend, structure including electrical contact means supported at saidfront end of said tubular body means, electrical leads connected to saidelectrical contact means and extending through said tubular body meanstowards said rear end, structure coupled to the front portion of saidtubular body means forming a portion of an outer annular slot andcomprising a surface which extends outward away from said front portionof said tubular body means, a ring shaped member located in said annularslot, said ring shaped member being of the type that can be expandedoutward from its axis and when released it will retract inwardly, anaxially movable sleeve means located around said tubular body means,said sleeve means being adapted to be moved between rearward and forwardpositions relative to said tubular body means, said sleeve means havingfront means forming another portion of said annular slot adapted toengage and force said ring shaped member outward against said surfacewhen said sleeve means is moved toward said forward position for movingsaid ring shaped member outward of said annular slot for use forlatching said test probe apparatus to structure of an opening, in saidrearward position of said sleeve means, said front means of said sleevemeans is located rearward of said ring shaped member sufficient to allowit to be released inwardly in said annular slot to an unlatchingposition, an annular rear slot formed in the outer wall of said tubularbody means, an annular rear slot formed in the inner wall of said sleevemeans, said annular rear slot being formed in said tubular body meansand in said sleeve means such that they are in alignment with each otherwhen said sleeve means is in its forward position relative to saidtubular body means and out of alignment with each other when said sleevemeans is in its rearward position relative to said tubular body means, asecond ring shaped member being of the type that can be expanded outwardfrom its axis and when released it will retract inwardly, said annularrear slot formed in the inner wall of said sleeve means having a sizesufficient to completely receive said second ring shaped member, saidannular rear slot formed in the outer wall of said tubular body meansbacking a size sufficient to only partially receive said second ringshaped member, said second ring shaped member being located around saidtubular body means out of and rearward of said annular rear slot formedin said tubular body means and in said annular rear slot formed in saidsleeve means when said sleeve means is in its rearward position relativeto said tubular body means, said second ring shaped member being locatedpartially in both of said annular rear slots when said sleeve means isin its forward position relative to said tubular body means forreleaseably holding said sleeve means in its forward position relativeto said tubular body means.
 11. A test probe apparatus,comprising:tubular body means having a front end and a rear end,structure including electrical contact means supported at said front endof said tubular body means, electrical leads connected to saidelectrical contact means and extending through said tubular body meanstowards said rear end, structure coupled to the front portion of saidtubular body means forming an outer annular slot, said annular slotbeing defined by forward and rearward facing wall means and inner wallmeans facing outward, at least a portion of said forward facing wallmeans being spaced radially outward from said inner wall means definingopening means leading to said annular slot between said forward facingwall means and said inner wall means, a ring shaped member located insaid annular slot, said ring shaped member being of the type that can beexpanded outward from its axis and when released it will retractinwardly, an axially movable sleeve means located around said tubularbody means, said sleeve means being adapted to be moved between rearwardand forward positions relative to said tubular body means, at least theforward portion of said sleeve means being movable in said openingmeans, said sleeve means having front means with groove means formed inthe outer surface thereof, in said forward position of said sleevemeans, said front means of said sleeve means is located between saidinner wall mans and said ring shaped member forcing at least portions ofsaid ring shaped member outward into said groove means of said sleevemeans for releasably holding said sleeve means in its forward positionrelative to said tubular body means and for use for latching said testprobe apparatus to structure of an opening, in said rearward position ofsaid sleeve means, said front means of said sleeve means is locatedrearward of said ring shaped member sufficient to allow it to bereleased inwardly in said annular slot to an unlatching position. 12.The test probe apparatus of claim 11 wherein said ring shaped membercomprises a helically wound spring member having two ends connectedtogether forming a toroidal shaped spring.
 13. The test probe apparatusof claim 11 wherein said ring shaped member comprises a non-metallic,elastic member.
 14. The test probe apparatus of claim 11, wherein:saidsleeve means has a rear end which is bifurcated forming two spaced apartend members, a block member having a first opening formed into its sideand a second opening formed in its end with said first and secondopenings intersecting each other, said rear end of said tubular bodymeans being located in said first opening and secured to said blockmember with said block member being located in the space between saidtwo spaced apart end members of said sleeve means such that said two endmembers move forward and rearward relative to said block member onopposite sides thereof as said sleeve means is moved between its forwardand rearward positions, said rear end of said tubular body means havingan opening formed therethrough in communication with said second openingof said block member forming a passage for said leads out of saidtubular body means.
 15. The test probe apparatus of claim 11,comprising:an annular rear slot formed in the outer wall of said tubularbody means, an annular rear slot formed in the inner wall of said sleevemeans, said annular rear slots being formed in said tubular body meansand in said sleeve means such that they are in alignment with each otherwhen said sleeve means is in its forward position relative to saidtubular body means and out of alignment with each other when said sleevemeans is in its rearward position relative to said tubular body means, asecond ring shaped member being of the type that can be expanded outwardfrom its axis and when released it will retract inwardly, said annularrear slot formed in the inner wall of said sleeve means having a sizesufficient to completely receive said second ring shaped member, saidannular rear slot formed in the outer wall of said tubular body meanshaving a size sufficient to only partially receive said second ringshaped member, said second ring shaped member being located around saidtubular body means out of and rearward of said annular rear slot formedin said tubular body means and in said annular rear slot formed in saidsleeve means when said sleeve means is in its rearward position relativeto said tubular body means, said second ring shaped member being locatedpartially in both of said annular rear slots when said sleeve means isin its forward position relative to said tubular body means forreleaseably holding said sleeve means in its forward position relativeto said tubular body means.
 16. The test probe apparatus of claim 15wherein said second ring shaped member comprises a helically woundspring member having two ends connected together forming a toroidalshaped spring.
 17. The test probe apparatus of claim 15 wherein saidsecond ring shaped member comprises a non-metallic elastic member.
 18. Atest probe apparatus, comprising:a tubular body member having a frontend and a rear end, structure including electrical contact meanssupported at said front end of said tubular body member, electricalleads connected to said electrical contact means and extending throughsaid tubular body member toward said rear end, tubular means having aforward tubular portion secured around said front end of said tubularbody member and a rear tubular portion spaced outward from said forwardtubular portion with a plurality of angularly spaced apart outwardextending wall means connecting said forward and rearward tubularportions, forming a plurality of angularly spaced apart apertures, aforward member coupled to said front end of said tubular body member,said forward member having a first portion for retaining an electricalcontact of said electrical contact means and a second portion whichextends to a position spaced forward of the forward edge of said reartubular portion of said tubular means defining an annular slotsurrounding a portion of said forward tubular portion of said tubularmeans, a ring shaped member located in said annular slot, said ringshaped member being of the type that can be expanded outward from itsaxis and when released it will retract inwardly, an axially moveablesleeve member located around said tubular body member, said sleevemember having a plurality of angularly spaced apart arm members at itsforward end adapted to extend through said apertures of said tubularmeans, said arm members having groove means formed in their outersurfaces, said sleeve member being slideably supported for axialmovement between forward and rearward positions relative to said tubularbody member, in said forward position of said sleeve member, said armmembers are located between said forward tubular portion of said tubularmeans and said ring shaped member forcing portions of said ring shapedmember into said groove means of said arm members and outward of saidannular slot for releaseably holding said sleeve member in its forwardposition relative to said tubular body member and for use for latchingsaid test probe apparatus to structure of an opening, in said rearwardposition of said sleeve member, said arm members are located rearward ofsaid ring shaped member sufficient to allow it to be released inwardlyin said annular slot to an unlatching position.
 19. The test probeapparatus of claim 18 wherein said ring shaped member comprises ahelically wound spring member having two ends connected together forminga toroidal shaped spring.
 20. The test probe apparatus of claim 18wherein said ring shaped member comprises a non-metallic elastic member.21. The test probe apparatus of claim 18, wherein:said sleeve member hasa rear end which is bifurcated forming two spaced apart end members, ablock member having a first opening formed into its side and a secondopening formed in its end with said first and second openingsintersecting each other, said rear end of said tubular body member beinglocated in said first opening and secured to said block member with saidblock member being located in the space between said two spaced apartend members of said sleeve member such that said two end members moveforward and rearward relative to said block member on opposite sidesthereof as said sleeve member is moved between its forward and rearwardpositions, said rear end of said tubular body member having an openingformed therethrough in communication with said second opening of saidblock member forming a passage for said leads out of said tubular bodymember.
 22. The test probe apparatus of claim 18, wherein:said forwardmember is coupled to said front end of said tubular body member by wayof said forward tubular portion of said tubular means.
 23. The testprobe apparatus of claim 18, comprising:an annular rear slot formed inthe outer wall of said tubular body member, an annular rear slot formedin the inner wall of said sleeve member, said annular rear slots beingformed in said tubular body member and in said sleeve member such thatthey are in alignment with each other when said sleeve member is in itsforward position relative to said tubular body member and out ofalignment with each other when said sleeve member is in its rearwardposition relative to said tubular body member, a second ring shapedmember of the type that can be expanded outward from its axis and whenreleased it will retract inwardly, said annular rear slot formed in theinner wall of said sleeve member having a size sufficient to completelyreceive said second ring shaped member, said annular rear slot formed inthe outer wall of said tubular body member having a size sufficient toonly partially receive said second ring shaped member, said second ringshaped member being located around said tubular body member out of andrearward of said annular rear slot formed in said tubular body memberand in said annular rear slot formed in said sleeve member when saidsleeve member is in its rearward position relative to said tubular bodymember, said second ring shaped member being located partially in bothof said annular rear slots when said sleeve member is in its forwardposition relative to said tubular body member for releaseably holdingsaid sleeve member in its forward position relative to said tubular bodymember.
 24. The test probe apparatus of claim 23, wherein said secondring shaped member comprises a helically wound spring member having twoends connected together forming a toroidal shaped spring.
 25. The testprobe apparatus of claim 23, wherein said second ring shaped membercomprises a non-metallic elastic member.
 26. A test probe apparatus,comprising:a tubular body member having a front end and a rear end,structure including electrical contact means supported at said front endof said tubular body member, electrical leads connected to saidelectrical contact means and extending through said tubular body membertoward said rear end, a bushing member having a forward cylindricalportion secured around said front end of said tubular body member and arear cylindrical portion spaced radially outward from said forwardcylindrical portion with a radially extending wall connecting saidforward and rearward cylindrical portions, a plurality of angularlyspaced apart apertures formed through said radially extending wall, ashell member secured around said front end of said tubular body member,said shell member having a front portion for retaining an electricalcontact of said electrical contact means and a rear portion whichextends to a position spaced forward of the forward edge of said rearcylindrical portion of said bushing member defining an annular slotsurrounding a portion of said forward cylindrical portion of saidbushing member, a ring shaped member located in said annular slot, saidring shaped member being of the type that can be expanded outward fromits axis and when released it will retract inwardly, an axially moveablesleeve member located around said tubular body member, said sleevemember having a plurality of angularly spaced apart arm members at itsforward end adapted to extend through said apertures of said bushingmember and being slideably supported for axial movement by said forwardcylindrical portion of said bushing member, said arm members havinggroove means formed in their outer surfaces, said sleeve member having arear portion slideably supported for axial movement by said tubular bodymember, said sleeve member being slideably supported for axial movementbetween forward and rearward positions relative to said tubular bodymember, in said forward position of said sleeve member, said arm membersare located between said forward cylindrical portion of said bushingmember and said ring shaped member forcing portions of said ring shapedmember radially outward into said groove means of said arm members forreleaseably holding said sleeve member in its forward position relativeto said tubular body member and for use for latching said test probeapparatus to structure of an opening, in said rearward position of saidsleeve member, said arm members are located rearward from said ringshaped member sufficient to allow it to be released radially inward insaid annular slot to an unlatching position.
 27. The test probeapparatus of claim 26, wherein said ring shaped member comprises ahelically wound spring member having two ends connected together forminga toroidal shaped spring.
 28. The test probe apparatus of claim 26,wherein said ring shaped member comprises a non-metallic elastic member.29. The test probe apparatus of claim 26, wherein:said sleeve member hasa rear end which is bifurcated forming two spaced apart end members, ablock member having a first opening formed into its side and a secondopening formed in its end with said first and second openingintersecting each other, said rear end of said tubular body member beinglocated in said first opening and secured to said block member with saidblock member being located in the space between said two spaced apartend members of said sleeve member such that said two end members moveforward and rearward relative to said block member on opposite sidesthereof as said sleeve member is moved between its forward and rearwardpositions, said rear end of said tubular body member having an openingformed therethrough in communication with said second opening of saidblock member forming a passage for said leads out of said tubular bodymember.
 30. A test probe apparatus, comprising:a tubular body memberhaving a front end and a rear end, structure including electricalcontact means supported at said front end of said tubular body member,electrical leads connected to said electrical contact means andextending through said tubular body member toward said rear end, acylindrical means having a forward cylindrical portion secured aroundsaid front end of said tubular body member and a rear cylindricalportion spaced radially outward from said forward cylindrical portionwith a plurality of angularly spaced apart radially extending wall meansconnecting said forward and rearward cylindrical portions, forming aplurality of angularly spaced apart apertures between said forward andrear cylindrical portions, a forward member coupled to the front end ofsaid forward cylindrical portion, said forward member having an innerportion for retaining an electrical contact of said electrical contactmeans and an outer portion which extends to a position spaced forward ofthe forward edge of said rear cylindrical portion of said cylindricalmeans defining an annular slot surrounding a portion of said forwardcylindrical portion of said cylindrical means, a ring shaped memberlocated in said annular slot, said ring shaped member being of the typethat can be expanded outward from its axis and when released it willretract inwardly, an axially moveable sleeve member located around saidtubular body member, said sleeve member having a plurality of angularlyspaced apart arm members at its forward end adapted to extend throughsaid apertures of said cylindrical means and being slideably supportedfor axial movement by said forward cylindrical portion of saidcylindrical means, said sleeve member having a rear portion slideablysupported for axial movement by said tubular body member, said sleevemember being slideably supported for axial movement between forward andrearward positions relative to said tubular body member, in said forwardposition of said sleeve member, said arm members are located betweensaid forward cylindrical portion of said cylindrical means and said ringshaped member forcing portions of said ring shaped member radiallyoutward for use for latching said test probe apparatus to structure ofan opening, in said rearward position of said sleeve member, said armmembers are, located rearward from said ring shaped member sufficient toallow it to be released radially inward in said slot to an unlatchingposition.
 31. The test probe apparatus of claim 31, wherein said ringshaped member comprises a helically wound spring member having two endsconnected together forming a toroidal shaped spring.
 32. The test probeapparatus of claim 30, wherein said ring shaped member comprises anon-metallic elastic member.
 33. The test probe apparatus of claim 30,comprising:an annular rear slot formed in the outer wall of said tubularbody member, an annular rear slot formed in the inner wall of saidsleeve member, said annular rear slots being formed in said tubular bodymember and in said sleeve member such that they are in alignment witheach other when said sleeve member is in its forward position relativeto said tubular body member and out of alignment with each other whensaid sleeve member is in its rearward position relative to said tubularbody member, a second ring shaped member of the type that can beexpanded outward from its axis and when released it will retractinwardly, said annular rear slot formed in the inner wall of said sleevemember having a size sufficient to completely receive said second ringshaped member, said annular rear slot formed in the outer wall of saidtubular body member having a size sufficient to only partially receivesaid second ring shaped member, said second ring shaped member beinglocated around said tubular body out of and rearward of said annularrear slot formed in said tubular body member and in said annular rearslot formed in said sleeve member when said sleeve member is in itsrearward position relative to said tubular body member, said second ringshaped member being located partially in both of said annular rear slotswhen said sleeve member is in its forward position relative to saidtubular body member for releaseably holding said sleeve member in itsforward position relative to said tubular body.
 34. The test probeapparatus of claim 33, wherein said second ring shaped member comprisesa helically wound spring member having two ends connected togetherforming a toroidal shaped spring.
 35. The test probe apparatus of claim33, wherein said second ring shaped member comprises a non-metallicelastic member.
 36. A test probe apparatus, comprising:a tubular bodymember having a front end and a rear end, structure including electricalcontact means supported at said front end of said tubular body member,electrical leads connected to said electrical contact means andextending through said tubular body member toward said rear end, tubularmeans having a forward tubular portion secured around said front end ofsaid tubular body member and a rear tubular portion spaced outward fromsaid forward tubular portion with a plurality of angularly spaced apartoutward extending wall means connecting said forward and rearwardtubular portions, forming a plurality of angularly spaced apartapertures, a forward member coupled to said front end of said tubularbody member, said forward member having a first portion for retaining anelectrical contact of said electrical contact means and a second portionwhich extends to a position spaced forward of the forward edge of saidrear tubular portion of said tubular means defining an annular slotsurrounding a portion of said forward tubular portion of said tubularmeans, a ring shaped member located in said annular slot, said ringshaped member being of the type that can be expanded outward from itsaxis and when released it will retract inwardly, an axially moveablesleeve member located around said tubular body member, said sleevemember having a plurality of angularly spaced apart arm members at itsforward end adapted to extend through said apertures of said tubularmeans, said sleeve member being slideably supported for axial movementbetween forward and rearward positions relative to said tubular bodymember, in said forward position of said sleeve member, said arm membersare located between said forward tubular portion of said tubular meansand said ring shaped member forcing portions of said ring shaped memberoutward of said annular slot for latching purposes, in said rearwardposition of said sleeve member, said arm members are located rearward ofsaid ring shaped member sufficient to allow it to be released inwardlyin said annular slot to an unlatching position.
 37. The test probeapparatus of claim 36, wherein said ring shaped member comprises ahelically wound spring member having two ends connected together forminga toroidal shaped spring.
 38. The test probe apparatus of claim 36,wherein said ring shaped member comprises a non-metallic elastic member.39. The test probe apparatus of claim 36, wherein:said sleeve member hasa rear end which is bifurcated forming two spaced apart end members, ablock member having a first opening formed into its side and a secondopening formed in its end with said first and second openingsintersecting each other, said rear end of said tubular body member beinglocated in said first opening and secured to said block member with saidblock member being located in the space between said two spaced apartend members, said sleeve member such that said two end members moveforward and rearward relative to said block member on opposite sidesthereof as said sleeve member is moved between its forward and rearwardpositions, said rear end of said tubular body member having an openingformed therethrough in communication with said second opening of saidblock member forming a passage for said leads out of said tubular bodymember.
 40. A test probe apparatus, comprising:tubular body means havinga front end and a rear end, structure including electrical contact meanssupported at said front end of said tubular body means, electrical leadsconnected to said electrical contact means and extending through saidtubular body means towards said rear end, structure coupled to the frontportion of said tubular body means forming a portion of an outer annularslot and comprising a surface which extends outward away from said frontportion of said tubular body means, a ring shaped member located in saidannular slot, said ring shaped member being of the type that can beexpanded outward from its axis and when released it will retractinwardly and comprising a helically wound metallic spring member havingtwo ends connected together forming a toroidal shaped spring member, anaxially movable sleeve means located around said tubular body means,said sleeve means being adapted to be moved between rearward and forwardpositions relative to said tubular body means, said sleeve means havingfront means forming another portion of said annular slot adapted toengage and force said toroidal shaped spring member to move forward andto expand outward against said surface when said sleeve means is movedtoward said forward position for moving said toroidal shaped springmember outward of said annular slot for use for latching said test probeapparatus to structure of an opening, said surface being shaped to allowsaid toroidal shaped spring member to move forward and to expand outwardagainst said surface upon engagement by said front means of said sleevemeans and when said sleeve means is moved toward said forward position,in said rearward position of said sleeve means, said front means of saidsleeve means is located rearward of said toroidal shaped spring membersufficient to allow it to be released inwardly in said annular slot toan unlatching position.
 41. The test probe apparatus of claim 40 whereinsaid surface comprises a frustum of a cone which extends outward awayfrom said front portion of said tubular body means.
 42. The test probeof claim 10, whereinsaid ring shaped member comprises a helically woundmetal spring member having two ends connected together forming atoroidal shaped spring member, said surface being shaped to allow saidtoroidal shaped spring member to move forward and to expand outwardagainst said surface upon engagement by said front means of said sleevemeans and when said sleeve means is moved toward said forward position.43. The test probe apparatus of claim 42 wherein said surface comprisesa frustum of a cone which extends outward away from said front portionof said tubular body means.